32 bit ARM guest on aarch64 host

[Richard W.M. Jones]

I've been trying to get a 32 bit Fedora/armv7hl guest to boot on a
64 bit Fedora/aarch64 host.

Host: Fedora Rawhide, aarch64 on Mustang

Guest: Fedora 22 disk image from:

  $ virt-builder --arch armv7l fedora-22

I should say that:

(1) I can boot this guest using an external <kernel> and <initrd> and
some hand written libvirt XML.  However external kernel is not very
flexible, since it means you have to do a dance on the host each time
you update the guest.

(2) I can boot this guest on x86-64 host using external kernel.

(3) It doesn't boot with UEFI in the guest, but that is expected since
the guest doesn't contain a UEFI bootloader, and I'm not even sure if
there is such a thing as UEFI for 32 bit ARM.

Anyway, I attempted to boot this disk image without the external
kernel hack using:

  $ virt-install --arch armv7l --import --name test3 --ram 2048 --disk
path=/var/tmp/test3.qcow2,format=qcow2 --os-variant fedora22

but it just hangs with a blank console, and with qemu-system-aarch64 [sic]
using 100% CPU.  I poked around inside the disk image, and there seems
to be no evidence that it booted, eg. no logs, no updated timestamps.

Should I try a newer guest?  I am going to try updating to Fedora 23.

Is it even possible to boot a 32 bit disk image without external
kernel?

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

[Richard W.M. Jones]

On Sat, Feb 27, 2016 at 01:33:26PM +0000, Richard W.M. Jones wrote:
>  Should I try a newer guest?  I am going to try updating to Fedora 23.
Same thing.

Attached is the qemu command line.  In this run I'm using some
hand-constructed XML, not 'virt-install --import' as before, but AFAIK
all important options are the same.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top

[Dennis Gilmore]

On Saturday, February 27, 2016 03:44:04 PM Richard W.M. Jones wrote:
>  On Sat, Feb 27, 2016 at 01:33:26PM +0000, Richard W.M. Jones wrote:
>  > Should I try a newer guest?  I am going to try updating to Fedora 23.
>  
>  Same thing.
>  
>  Attached is the qemu command line.  In this run I'm using some
>  hand-constructed XML, not 'virt-install --import' as before, but AFAIK
>  all important options are the same.
>  
>  Rich. 
It is currently not possible to boot a 32 bit arm vm without an external 
kernel and initrd. I have played with having a u-boot that will work. But 
right now you would need to construct the guest to match the specs hardcoded 
into u-boot. It is a problem that needs to be solved

Dennis

[Richard W.M. Jones]

On Sat, Feb 27, 2016 at 10:45:55AM -0600, Dennis Gilmore wrote:
>  On Saturday, February 27, 2016 03:44:04 PM Richard W.M. Jones wrote:
>  > On Sat, Feb 27, 2016 at 01:33:26PM +0000, Richard W.M. Jones wrote:
>  > > Should I try a newer guest?  I am going to try updating to Fedora 23.
>  > 
>  > Same thing.
>  > 
>  > Attached is the qemu command line.  In this run I'm using some
>  > hand-constructed XML, not 'virt-install --import' as before, but AFAIK
>  > all important options are the same.
>  > 
>  > Rich.
>  It is currently not possible to boot a 32 bit arm vm without an external 
>  kernel and initrd. I have played with having a u-boot that will work. But 
>  right now you would need to construct the guest to match the specs hardcoded 
>  into u-boot. It is a problem that needs to be solved 
Thanks Dennis.  When you say you've played with u-boot, does that mean
booting with an external u-boot binary?  That would be a considerable
improvement over external kernel.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

[Dennis Gilmore]

On 2016-02-27 11:59, Richard W.M. Jones wrote:
>  On Sat, Feb 27, 2016 at 10:45:55AM -0600, Dennis Gilmore wrote:
> > On Saturday, February 27, 2016 03:44:04 PM Richard W.M. Jones wrote:
> > > On Sat, Feb 27, 2016 at 01:33:26PM +0000, Richard W.M. Jones wrote:
> > > > Should I try a newer guest?  I am going to try updating to Fedora 23.
> > >
> > > Same thing.
> > >
> > > Attached is the qemu command line.  In this run I'm using some
> > > hand-constructed XML, not 'virt-install --import' as before, but AFAIK
> > > all important options are the same.
> > >
> > > Rich.
> > It is currently not possible to boot a 32 bit arm vm without an 
> > external
> > kernel and initrd. I have played with having a u-boot that will work. 
> > But
> > right now you would need to construct the guest to match the specs 
> > hardcoded
> > into u-boot. It is a problem that needs to be solved
>  
>  Thanks Dennis.  When you say you've played with u-boot, does that mean
>  booting with an external u-boot binary?  That would be a considerable
>  improvement over external kernel.
>  
>  Rich. 
Yes I have used u-boot as a kernel. its very rough and not really a good 
experience, at least in that you have to configure the vm the same as 
u-boot was built.

[Cole Robinson]

On 02/28/2016 11:38 PM, Dennis Gilmore wrote:
>  On 2016-02-27 11:59, Richard W.M. Jones wrote:
> > On Sat, Feb 27, 2016 at 10:45:55AM -0600, Dennis Gilmore wrote:
> >> On Saturday, February 27, 2016 03:44:04 PM Richard W.M. Jones wrote:
> >> > On Sat, Feb 27, 2016 at 01:33:26PM +0000, Richard W.M. Jones wrote:
> >> > > Should I try a newer guest?  I am going to try updating to Fedora 23.
> >> >
> >> > Same thing.
> >> >
> >> > Attached is the qemu command line.  In this run I'm using some
> >> > hand-constructed XML, not 'virt-install --import' as before, but
> AFAIK
> >> > all important options are the same.
> >> >
> >> > Rich.
> >> It is currently not possible to boot a 32 bit arm vm without an external
> >> kernel and initrd. I have played with having a u-boot that will work. But
> >> right now you would need to construct the guest to match the specs hardcoded
> >> into u-boot. It is a problem that needs to be solved
> >
> > Thanks Dennis.  When you say you've played with u-boot, does that mean
> > booting with an external u-boot binary?  That would be a considerable
> > improvement over external kernel.
> >
> > Rich.
>  Yes I have used u-boot as a kernel. its very rough and not really a good
>  experience, at least in that you have to configure the vm the same as u-boot
>  was built. 
There's uboot builds that work with qemu + arm vexpress, courtesy of Gerd:

http://blog.wikichoon.com/2014/11/booting-fedora-21-arm-with-qemu-and-u.html

But uboot isn't going to work with qemu-system-arm -M virt because uboot
doesn't have any virtio support

- Cole

[Marcin Juszkiewicz]

W dniu 27.02.2016 o 14:33, Richard W.M. Jones pisze:
>  I've been trying to get a 32 bit Fedora/armv7hl guest to boot on
> a
>  64 bit Fedora/aarch64 host.
>
>  Host: Fedora Rawhide, aarch64 on Mustang
>
>  Guest: Fedora 22 disk image from:
>
>     $ virt-builder --arch armv7l fedora-22 
I used virt-manager for it:

https://marcin.juszkiewicz.com.pl/2016/01/17/running-32-bit-arm-virtual-m...